Pumping moms know that pumped breastmilk takes up a significant amount of refrigerator and freezer space. While all of the extra milk is a huge win (yay!) you don't want to only have space for milk (I mean, where would you store your Moosetracks ice cream?!)
Kind of kidding, but the space issue is a real issue. And not only that, but your breastmilk needs to be easily accessible and organized so that it can serve its purpose.